According to the u. s. robinson patman act of 1936, price discrimination a. may be used to drive rivals out of business. b. is legal unless it harms competition. c. can only be justified if the price discrimination is due to actual cost differences. d. is always illegal.

The amount of flow through a solenoid valve in an automobile's pollution-control system is an important characteristic. an experiment was carried out to study how flow rate depended on three factors: armature length, spring load, and bobbin depth. four different levels (low, fair, moderate, and high) of each factor were chosen, and a single observation on flow was made for each combination of levels.